French artist Laure Prouvost has won Britain's Turner prize for contemporary art for her video installation set among a mock-tea party setting.

"The jury thought her work was outstanding for its complex and courageous combination of images and objects in a deeply atmospheric environment," said an official press release from Tate, the award's partners.

Young Irish actress Saoirse Ronan, who starred in 2007 film Atonement, presented Prouvost the $40,000 award for her work, entitled Wantee, at a ceremony in Londonderry, Northern Ireland.

"I'm not ready, I didn't expect it at all," the surprise winner said.

"Four incredible artists are here with me and the show. I thought it can't be me, I was sure it was not me. So thank you everybody.

"Thank you for adopting me, for having a French one [winner], I feel adopted by the UK," she added.

"I've been here half my life. My boyfriend is half British and my daughter is both. It was really this country that let me grow."

The prize is unique in Britain in the way it sparks a debate among people who are not normally interested in art, with notorious British artists Damien Hirst and Tracey Emin helping to raise its profile.

The four nominees created a typically eclectic collection for this year's prize exhibition in Londonderry, the first time it has been staged outside England.

The work that got many visitors scratching their heads was Tino Sehgal's This is Exchange, an empty room where guests are offered a small amount of money to engage in conversations about the market economy.

Thank you for adopting me, for having a French one [winner], I feel adopted by the UK. I've been here half my life, my boyfriend is half British and my daughter is both [and French]. It was really this country that let me grow.

Turner Prize winner Laure Prouvost

Another entry, David Shrigley's Life Mode, a larger-than-life naked humanoid robot which blinks and periodically urinates, was judged too offensive for some visiting school groups.

The most conventional artist to be nominated was Lynette Yiadom-Boakye, a portrait artist of Ghanaian descent and the first black woman to be shortlisted for the prize.

But it was Prouvost's study on the frustrations of an artist that most impressed the judges.

The visual piece, full of quick cuts and montage, shows art work created by Prouvost's fictional grandfather being used by his wife for household chores, symbolising the lack of control an artist often has over their output.

The video was a response to the artist Kurt Schwitters, and the title Wantee comes from Schwitters' girlfriend, because she frequently asked "want tea?"

Judges called the piece "unexpectedly moving", adding that the artist "takes viewers to an inner world, while making reference to the streaming of images in a post-Internet age".

Prouvost was born in Croix-Lille, but moved to London to study at the city's Goldsmiths College and Central St Martins.

She is known for films and installations "characterised by richly layered narrative, language, translation, and surreal interruptions," according to Tate.

The prize was established in 1984 by the Tate gallery in London in honour of 19th-century J. M. W. Turner, who had long wished to set up an award for younger artists.

It is open to any contemporary artist under the age of 50 who is living, working or born in Britain, and is judged on the work they have put on in the last 12 months.

The controversy that surrounded previous entries - notably Emin's My Bed in 1999, an unmade bed full of empty vodka bottles, used condoms and soiled underwear - has subsided as contemporary art has become commonplace.

The prize is part of the celebrations for the 2013 UK City of Culture in Londonderry, which is best known for one of the worst episodes of the violence in Northern Ireland.

The exhibition has been staged at the former Ebrington barracks, where British soldiers were based when they fired on civil rights protesters on Bloody Sunday in 1972.

An inquiry in 2010 found that all 14 people killed and many more injured were unarmed and completely innocent.